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What is excretion?
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It's transfer toxic wastes in your body to the environment, It's produce from lungs, kidneys, sweat glands, intestine.

Living things can excretion(produce wastes) like:
Carbon Dioxide(Co2)
Nitrogen.
Urine.(Pee)vomit.jpg
Fecal matter(Poo)
Vomit.
Sweat.
Fart.
Burp.
Mucus
.

Why is removing waste important for your body?
Body cells will make the food you eat into toxic. Toxic is very bad for you so you need to get rid of it. When you are getting rid of it, that step is called poop.

How is waste useful?
It can be used in incinerators which produce heat as for burning fossil fuels (fuel)
Proteins:
1. Are the building blocks of all living things.
2. Are used to make enzymes.
3.A kind of fungi called yeast. It produce alcohol instead of waste to make beer, whiskey and wine.
4.Plants inhaling in Co2 exhaling oxygen.

Where do fart comes from?
Fart comes from several sources: air we swallow, chemical reactions in our guts, bacteria living in our guts.

Why do we burp?
We burp because when you eat or drink, you swallow air and food or drink at the same time. Usually the air that you swallow in must go out so when the stomach force it to go out. So it makes noise and that is burp. You can burp loudly when you drink liquid that have Co2 like: Pepsi, Beer, Fanta, Coca Cola, Sprite or 7up. You can also burp when you eat or drink very fast, it can send extra air into your stomach. You can burp a few times a day but if you burp a lot per day, you should see the doctor because there might be something wrong with your body.


What help the body to excret?
Kidneys:
We all have kidneys and their job is to filter the blood, the waste then become urine and goes down the toilet. Every day the kidneys check every drop of blood 36 times and produce 1.5 liters of urine.

Nose and Lungs.
30% of oxygen breath out without being used, When we breathe out, the body relaxes the diaphragm muscle( a muscle sheet of muscle under the lung)and lower the ribcage, forcing air from the lungs.

Sweat glands.
Your body keeps its inside temperature 37 Celsius, when your body heats up, it produces a watery fluid called sweat, it helps you to cool off and it's like taking a small shower.

Cited Source:
http://www.heptune.com/farts.html - have good information
http://kidshealth.org/kid/talk/yucky/burp.html - funny but good information

http://upload.wikimedia.org/wikipedia/commons/7/7e/Kidney_PioM.png
Horrible Science:"The Body Owner's Handbook" and "Blood, Bones and Body Bits" by Nick Arnold, illustrated by Tony De Saulles.
Available in UNIS Hanoi library.
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Authors:
Thai Son Trinh, Ewa Lachman, Carole Shaphyr, Vu Bui.